Passenger Aviation and High Speed Rail: A Comparison of Emissions Profiles on Selected European Routes

Air transport has been constantly growing and forecasts seem to confirm the trend; the resulting environmental impact is relevant, both at local and at global scale. In this paper, data from various datasets have been integrated to assess the environmental impact of modal substitution with high speed rail. Six intra-EU28 routes and a domestic route have been defined for comparison. The airports have been chosen considering the share of the total number of passengers on flights to/from other EU Member States. Three scenarios have been proposed in the time period 2017-2025; aircraft types, distance bands, and occupancy rate are investigated on each scenario. The comparison with HSR service has been carried out only on passenger service and not for freight. The energy consumption and the consequent emissions for the aircraft have been estimated on the base of the available data for the mix of aircraft types, performing the routes. The results indicate the advantage of the high speed trains, in terms of direct CO2eq emissions per passenger km. Compared to a neutral scenario, with an annual passenger increment of 3.5%, the HSR substitution of the 5% and the 25% of this increment allow a GHG saving of 4% and 20%, respectively. Some of the analysed routes (e.g., Frankfurt Main-Paris CDG) have interesting GHG savings but the duration of the trip today is limiting for a real substitution. Moreover, there is general agreement that the extreme weather events induced by climate change will affect the functioning of the European transport system. In this sense, transportation by the rail mode is expected to play a significant role in strengthening the EU transport system, its resilience, and its reliability, as it is less immediately subject to the impacts of severe weather conditions.